Problem: Recently, Anton has found a set. The set consists of small English letters. Anton carefully wrote out all the letters from the set in one line, separated by a comma. He also added an opening curved bracket at the beginning of the line and a closing curved bracket at the end of the line. 

Unfortunately, from time to time Anton would forget writing some letter and write it again. He asks you to count the total number of distinct letters in his set.

Input

The first and the single line contains the set of letters. The length of the line doesn't exceed 1000. It is guaranteed that the line starts from an opening curved bracket and ends with a closing curved bracket. Between them, small English letters are listed, separated by a comma. Each comma is followed by a space.

Output

Print a single number — the number of distinct letters in Anton's set.

Examples

Input

{a, b, c}


Output

3


Input

{b, a, b, a}


Output

2


Input

{}


Output

0

Solution (in PYTHON3):

Solution:
'''
def main():
    from sys import stdin,stdout
if __name__=='__main__':
    main()
'''
#1A
'''
def main():
    from sys import stdin,stdout
    from math import ceil
    n,m,a=map(int,stdin.readline().split())
    stdout.write(str(ceil(n/a)*ceil(m/a)))
if __name__=='__main__':
    main()
'''
#4A
'''
def main():
    from sys import stdin,stdout
    i=int(stdin.readline())
    if i&1:
        stdout.write('NO\n')
    else:
        if i//2 >1:
            stdout.write('YES\n')
        else:
            stdout.write('NO\n')
if __name__=='__main__':
    main()
'''
#71A
'''
def main():
    from sys import stdin,stdout
    for _ in range(int(stdin.readline())):
        s=stdin.readline().strip()
        if len(s) <=10:
            stdout.write(s+'\n')
        else:
            stdout.write(s[0]+str(len(s[1:-1]))+s[-1]+'\n')
if __name__=='__main__':
    main()
'''
#158A
'''
def main():
    from sys import stdin,stdout
    n,k=map(int,stdin.readline().split())
    a=list(map(int,stdin.readline().split()))
    count=0
    for i in range(n):
        if a[i] and a[i]>=a[k-1]:
            count+=1
    stdout.write(str(count))
if __name__=='__main__':
    main()
'''
#188A
'''
def main():
    from sys import stdin,stdout
    s=stdin.readline().strip()
    t=''
    s=s.lower()
    for i in s:
        if i not in 'aeiouy':
            t+='.'+i
    stdout.write(t)
if __name__=='__main__':
    main()
'''
#50A
'''
def main():
    from sys import stdin,stdout
    n,m=map(int,stdin.readline().split())
    stdout.write(str((n*m)//2))
if __name__=='__main__':
    main()
'''
#231A
'''
def main():
    from sys import stdin,stdout
    count=0
    for _ in range(int(stdin.readline())):
        if sum(list(map(int,stdin.readline().split())))>=2:
            count+=1
    stdout.write(str(count))
if __name__=='__main__':
    main()
'''
#282A
'''
def main():
    from sys import stdin,stdout
    x=0
    for _ in range(int(stdin.readline())):
        s=stdin.readline().strip()
        if '++' in s:
            x+=1
        elif '--' in s:
            x-=1
    stdout.write(str(x))
if __name__=='__main__':
    main()
'''
#158B
'''
def main():
    from sys import stdin,stdout
    n=int(stdin.readline())
    l=sorted(list(map(int,stdin.readline().split())))
    counter=l.count(4)
    l=l[:n-counter]
    i=0
    while len(l):
        if len(l)==1:
            counter+=1
            break
        
    stdout.write(str(counter))
if __name__=='__main__':
    main()
'''
#96A
'''
def main():
    from sys import stdin,stdout
    s=stdin.readline().strip()
    count=1
    flag=0
    for i in range(1,len(s)):
        if s[i]==s[i-1]:
            count+=1
            if count >=7:
                flag=1
                break
        else:
            count=1
    if flag:
        stdout.write('YES')
    else:
        stdout.write('NO')
if __name__=='__main__':
    main()
'''
#116A
'''
def main():
    from sys import stdin,stdout
    maxim=0
    total=0
    for _ in range(int(stdin.readline())):
        a,b=map(int,stdin.readline().split())
        total+=(b-a)
        if total >maxim:
            maxim=total
    stdout.write(str(maxim))
if __name__=='__main__':
    main()
'''
#112A
'''
def main():
    from sys import stdin,stdout
    s=stdin.readline().strip().lower()
    t=stdin.readline().strip().lower()
    if s==t:
        stdout.write('0')
    elif s < t:
        stdout.write('-1')
    else:
        stdout.write('1')
if __name__=='__main__':
    main()
'''
#339A
'''
def main():
    from sys import stdin,stdout
    l=list(map(str,stdin.readline().strip().split('+')))
    l.sort()
    stdout.write('+'.join(l))
if __name__=='__main__':
    main()
'''
#131A
'''

def main():
    from sys import stdin,stdout
    s=stdin.readline().strip()
    if s.isupper():
        stdout.write(s.lower())
    elif (s[0].islower() and s[1:].isupper()) or (len(s)==1 and s.islower()):
        stdout.write(s.title())
    else:
        stdout.write(s)
if __name__=='__main__':
    main()
'''
#266A
'''
def main():
    from sys import stdin,stdout
    n=int(stdin.readline())
    count=0
    s=stdin.readline().strip()
    for i in range(1,n):
        if s[i]==s[i-1]:
            count+=1
    stdout.write(str(count))
if __name__=='__main__':
    main()
'''
#133A
'''
def main():
    from sys import stdin,stdout
    s=stdin.readline().strip()
    if 'H' in s or 'Q' in s or '9' in s:
        stdout.write('YES')
    else:
        stdout.write('NO')
if __name__=='__main__':
    main()
'''
#281A
'''
def main():
    from sys import stdin,stdout
    s=stdin.readline().strip()
    stdout.write(s[0].upper()+s[1:])
if __name__=='__main__':
    main()
'''
#58A
'''
def main():
    from sys import stdin,stdout
    test='hello'
    s=stdin.readline().strip()
    while len(test) and len(s):
        if test[0]==s[0]:
            test=test[1:]
            s=s[1:]
        else:
            s=s[1:]
    if test=='':
        stdout.write('YES')
    else:
        stdout.write('NO')
if __name__=='__main__':
    main()
'''
#236A
'''
def main():
    from sys import stdin,stdout
    if len(set(stdin.readline().strip())) & 1:
        stdout.write('IGNORE HIM!')
    else:
        stdout.write('CHAT WITH HER!')
if __name__=='__main__':
    main()
'''
#467A
'''
def main():
    from sys import stdin,stdout
    count=0
    for _ in range(int(stdin.readline())):
        a,b=map(int,stdin.readline().split())
        if b-a>=2:
            count+=1
    stdout.write(str(count))
if __name__=='__main__':
    main()
'''
#148A
'''
def main():
    from sys import stdin,stdout
    k=int(stdin.readline())
    l=int(stdin.readline())
    m=int(stdin.readline())
    n=int(stdin.readline())
    d=int(stdin.readline())
    count=0
    for i in range(1,d+1):
        if i % k and i % l and i % m and i % n:
            count+=1
    stdout.write(str(d-count))
if __name__=='__main__':
    main()
'''
#263A
'''
def main():
    from sys import stdin,stdout
    for i in range(5):
        a=list(map(int,stdin.readline().split()))
        try:
            x=a.index(1)+1
            y=i+1
        except:
            g=''
    stdout.write(str(abs(x-3)+abs(y-3)))
if __name__=='__main__':
    main()
'''
#546A
'''
def main():
    from sys import stdin,stdout
    k,n,w=map(int,stdin.readline().split())
    m=(w*(w+1)*k)//2
    if m<=n:
        stdout.write('0')
    else:
        stdout.write(str(m-n))
if __name__=='__main__':
    main()
'''
#136A
'''
def main():
    from sys import stdin,stdout
    n=int(stdin.readline())
    l=list(map(int,stdin.readline().split()))
    p=[0 for _ in range(n)]
    for i in range(n):
        p[l[i]-1]=i+1
    stdout.write(' '.join(str(x) for x in p))
if __name__=='__main__':
    main()
'''
#122A
'''
def main():
    l=[]
    for i in range(4,1001):
        s=str(i)
        flag=1
        for element in s:
            if element !='4' and element !='7':
                flag=0
                break
        if flag:
            l.append(i)
    from sys import stdin,stdout
    n=int(stdin.readline())
    for i in l:
        if n%i==0:
            stdout.write('YES')
            return
    stdout.write('NO')
if __name__=='__main__':
    main()
'''
#266B
'''
def main():
    from sys import stdin,stdout
    n,x=map(int,stdin.readline().split())
    s=stdin.readline().strip()
    for _ in range(x):
        s=s.replace('BG','GB')
    stdout.write(s)
if __name__=='__main__':
    main()
'''
#271A
'''
def main():
    from sys import stdin,stdout
    n=int(stdin.readline())
    n+=1
    while True:
        if len(str(n))==len(set(str(n))):
            break
        else:
            n+=1
    stdout.write(str(n))
if __name__=='__main__':
    main()
'''
#41A
'''
def main():
    from sys import stdin,stdout
    a=stdin.readline().strip()
    b=stdin.readline().strip()
    if a==b[-1::-1]:
        stdout.write('YES')
    else:
        stdout.write('NO')
if __name__=='__main__':
    main()
'''
#160A
'''
def main():
    from sys import stdin,stdout
    n=int(stdin.readline())
    l=sorted(list(map(int,stdin.readline().split())))
    p=l[-1]
    lsum=sum(l[:-1])
    l=l[:-1]
    count=1
    while lsum >= p:
        p+=l[-1]
        lsum-=l[-1]
        l=l[:-1]
        count+=1
    stdout.write(str(count))
if __name__=='__main__':
    main()
'''
#110A
'''
def main():
    from sys import stdin,stdout
    s=stdin.readline().strip()
    k=s.count('4')+s.count('7')
    if  k==4 or k==7:
        stdout.write('YES')
    else:
        stdout.write('NO')
if __name__=='__main__':
    main()
'''
#100989A
'''
def main():
    from sys import stdin,stdout
    stdout.write(str(int(stdin.readline())+1))
if __name__=='__main__':
    main()
'''
#100989C
'''
def main():
    from sys import stdin,stdout
    count=0
    for _ in range(int(stdin.readline())):
        a,b=map(int,stdin.readline().split())
        count+=(b-a)
    stdout.write(str(count))
if __name__=='__main__':
    main()
'''
#100989D
'''
def main():
    from sys import stdin,stdout
    n,q=map(int,stdin.readline().split())
    l=sorted(list(map(int,stdin.readline().split())))
    o=[]
    for i in range(n):
        o.append(0)
    while q:
        a,b=map(str,stdin.readline().split())
        if a =='in':
            b=int(b)
            flag=0
            for i in range(n):
                if b<=l[i] and o[i]==0:
                    o[i]=1
                    flag=1
                    break
            if flag:
                stdout.write(str(i+1)+'\n')
            else:
                stdout.write('-1\n')
        else:
            b=int(b)-1
            o[b]=0
        q-=1
if __name__=='__main__':
    main()
'''
#82A
'''
def main():
    from sys import stdin, stdout
    n=int(stdin.readline())
    while n>5:
        if n&1:
            n-=5
            n//=2
        else:
            n-=4
            n//=2
    if n==1:
        stdout.write('Sheldon')
    elif n==2:
        stdout.write('Leonard')
    elif n==3:
        stdout.write('Penny')
    elif n==4:
        stdout.write('Rajesh')
    else:
        stdout.write('Howard')
if __name__=='__main__':
    main()
'''
#460A
'''
WA
def main():
    from sys import stdin,stdout
    n,m=map(int,stdin.readline().split())
    counter=n
    while n>=m:
        counter+=n//m
        n//=m
    stdout.write(str(counter))
if __name__=='__main__':
    main()
'''
#479A
'''
def main():
    from sys import stdin,stdout
    a=int(stdin.readline())
    b=int(stdin.readline())
    c=int(stdin.readline())
    maxim=a*b*c
    if a+b+c > maxim:
        maxim=a+b+c
    if (a+b)*c >maxim:
        maxim=(a+b)*c
    if a*(b+c)>maxim:
        maxim=a*(b+c)
    if a+b*c > maxim:
        maxim=a+b*c
    stdout.write(str(maxim))
if __name__=='__main__':
    main()
'''
#69A
'''
def main():
    from sys import stdin,stdout
    a,b,c=0,0,0
    for _ in range(int(stdin.readline())):
        x,y,z=map(int,stdin.readline().split())
        a+=x
        b+=y
        c+=z
    if a or b or c:
        stdout.write('NO')
    else:
        stdout.write('YES')
if __name__=='__main__':
    main()
'''
#580A
'''
def main():
    from sys import stdin,stdout
    n=int(stdin.readline())
    l=list(map(int,stdin.readline().split()))
    max_so_far=1
    counter=1
    for i in range(1,n):
        if l[i]>=l[i-1]:
            counter+=1
        else:
            max_so_far=max(max_so_far,counter)
            counter=1
    stdout.write(str(max(max_so_far,counter)))
if __name__=='__main__':
    main()
'''
#337A
'''
def main():
    from sys import stdin,stdout
    n,m=map(int,stdin.readline().split())
    li=sorted(list(map(int,stdin.readline().split())))
    minim=100000
    for i in range(m-n+1):
        sub=li[i:i+n]
        d=0
        for i in range(1,len(sub)):
            d+=sub[i]-sub[i-1]
        minim=min(minim,d)
    stdout.write(str(minim))
if __name__=='__main__':
    main()
'''
#472A
'''
def main():
    from sys import stdin,stdout
    from math import floor,sqrt
    def check(n):
        if n==2:
            return True
        elif n & 1:
            for i in range(3,floor(sqrt(n))+1):
                if n % i==0:
                    return False
            return True
        else:
            return False
    n=int(stdin.readline())
    i=4
    while True:
        #print(check(i),check(n-i))
        if check(n-i) or check(i):
            i+=1
            continue
        else:
            stdout.write(str(i)+' '+str(n-i))
            break
if __name__=='__main__':
    main()
'''
#119A
'''
def main():
    def gcd(a,b):
        if b:
            return gcd(b,a%b)
        else:
            return a
    from sys import stdin,stdout
    a,b,n=map(int,stdin.readline().split())
    flag=0
    while n > 0:
        if flag:
            n-=gcd(n,b)
            flag=0
        else:
            n-=gcd(n,a)
            flag=1
    if flag:
        stdout.write('0')
    else:
        stdout.write('1')
if __name__=='__main__':
    main()
'''
#451A
'''
def main():
    from sys import stdin,stdout
    a,b=map(int,stdin.readline().split())
    if a==1 or b==1:
        stdout.write('Akshat')
    elif min(a,b)**2 & 1:
        stdout.write('Akshat')
    else:
        stdout.write('Malvika')
if __name__=='__main__':
    main()
'''
#379A
'''
def main():
    from sys import stdin,stdout
    a,b=map(int,stdin.readline().split())
    counter=a
    while a:
        counter+=a//b
        if a > b:
            d=a%b
        else:
            d=0
        a=(a+d)//b
    stdout.write(str(counter))
if __name__=='__main__':
    main()
'''
#208A
'''
def main():
    from sys import stdin,stdout
    s=stdin.readline().strip()
    stdout.write(s.replace('WUB',' ').strip())
if __name__=='__main__':
    main()
'''
#144A
'''
def main():
    from sys import stdin,stdout
    n=int(stdin.readline())
    t=tuple(map(int,stdin.readline().split()))
    maxim=t[0]
    imaxim=0
    minim=t[0]
    iminim=0
    for i in range(1,n):
        if t[i] > maxim:
            maxim=t[i]
            imaxim=i
        if t[i] <=minim:
            minim=t[i]
            iminim=i
    if imaxim > iminim:
        stdout.write(str(imaxim+n-iminim-2))
    else:
        stdout.write(str(imaxim+n-iminim-1))
if __name__=='__main__':
    main()
'''
#469A
'''
def main():
    from sys import stdin,stdout
    a=set()
    n=set(range(1,int(stdin.readline())+1))
    for i in range(2):
        a.update(tuple(map(int,stdin.readline().split()))[1:])
    if a==n:
        stdout.write('I become the guy.')
    else:
        stdout.write('Oh, my keyboard!')
if __name__=='__main__':
    main()
'''
#344A
'''
def main():
    from sys import stdin,stdout
    state=''
    counter=0
    for _ in range(int(stdin.readline())):
        s=stdin.readline()
        if s!=state:
            counter+=1
            state=s
    stdout.write(str(counter))
if __name__=='__main__':
    main()
'''
#443A
def main():
    from sys import stdin,stdout
    s=set(stdin.readline().strip()[1:-1].split(', '))
    if '' in s:
        stdout.write('0')
    else:
        stdout.write(str(len(s)))
if __name__=='__main__':
    main()